Art of stencil making



- parte Patented July 17, I923.

E ii STATES p I ,461,8t7 PATENT OFFICE.

STERLING ELLIOTT, OF CAMBRIDGE, MASSACHUSETTS; HARRIET ADELL ELLIOTT EX-ECUTBIX 0F SAID STERLING ELLIOTT, DECEASED.

'nnr or STENCIL MAKING.

Ito Drawing.

To all whom it may concern:

Be it known that I, STERLING ELLIOTT, a citizen of the United States,residing at Cambridge, in the county of Middlesex and State ofMassachusetts, have invented an Improvement in the Art of StencilMaking, of which the following is a specification.

This invention relates to the art of stencil making and has particularreference to a method of treating the paper in which thestencil-characters are impressed, by which it becomes strong andtoughpand in condition properly to receive the impressions and the ink.

I find that the best results are obtained with the use of a particulartype of Japanese paper known as Yoshino characterized by very longfibres and considerable strength for its lightweight. The finishedstencil has a coating of tempered gelatine on one side only which isadapted to be cut through and displaced in the process of making thestencil, but the fibres of the paper should remain intact. sage of inkfor printing only where the gelatine is cut through and the stencil maythereby print the characters previously formed in the stencil.

My'method comprises initially coating one side of the paper sheet fromwhich the individual stenclls are to be cut, with a layer of g'elatineand glycerine, and subsequently treating the coated sheet to temper thecoating b which added strength may be imto the prepared stencil paper.

In the performance of my method I first apply the gelatine coating as asolution of gelatine, glycerine and water and by any suitable means, toone side only of the sheet; and the coating solution is allowed toremain in contact with the sheetuntil it penetrates the paper. Care, of\course, must be taken that the paper sheet is uniformlycoated and thatthe solution uniformly permeates the paper from the coated side. f

I find that very satisfactory results are obtained by employing agelatine coating solution for the one side comprising the followingingredients and in about the following roportions: v

Gelatine, 8 ounds; glycerine, 11- pounds; water, 7% gal ons.

The amount of each ingredient of the coating solution is not fixehowever, and for best results, it is preferable to vary the The stencilallows the pas-- Application filed March 1, 1920. Serial No. 362,570.

relative amounts of the ingredients, especially in accordance withvariation of weather conditions.

After the paper sheet has been coated on one side with the gelatinesolution it is hung up and allowed to drain and dry. The

drying period usually takes place over night, or extends for about 10 or12 hours, and the paper is then in condition for further treatment.

The next step in the process consists in applying a gelatine-temperingand paperstrengthening solution (preferably also containing glycerine)to both sides of the partially drled sheet, preferably by dipping orimmersing the entire sheet in the solution.

The efiect of this step is to so toughen the gelatineas. to render itpractically unaffected by ordinary use. The glycerme content of thesolution aids materially in retaining the strength and flexibility ofthe sheet.

The toughening solution comprises, preferably, alum, 3 pounds;glycerine, 3 gallons;

water, 12 gallons.

The relative amounts may be varied somewhat, to obtain uniform results.

The condition of the finished sheet is indicated to the practicalobserver by noting the character of and resistance to tear of thetreated sheet.

After the finished sheets have been hung up for draining and drying theyare in condition to be cut and manufactured into stencils.

The paper, so treated, is exceptionally strong, as contrasted with itsstrength before treatment, and is very flexible andwill remain in thiscondition for a long period.

But one side of the paper sheet 15 coated and the-other or non-gelatinewith gelatine, coated side is adapted to contact with the material to bestencilled.

I claim:

1. The method of preparing stencil sheets which consists in initiallytreating the sheet on one side only with a solution containing gelatineand water, and subsequently coating both sides of the sheet with asolution consisting of alum, glycerine and water.

2. The method of preparing stencil sheets which consists in treating thesheet-on one side only with a solution consisting of gelatine, glycerineand water, allowing the water to evaporate and subsequently immersing Ithe sheet in a solution containing. glycerine, 'alum'and water.-' j 3.The method of preparing stencil'sheets which consists in treating thesheet on one.

5 side only with a gelatineand glycerine solution until the paper isermeated from the treated side, allowing t e waterof the solution toevaporate, and subsequently treating the sheet on both sides wit a so-10 lution containing alum, glycerine an water. 4. The method ofpreparing a stencil sheet .which consists in applying a solution'con-.of gelatineion the coated and tempering the gelatine coating and theslsting of gelatine, gly'cerme and water to paper sheet, permitting dry.and form a layer side of the sheet,

one side only of a the coated sheet to material composing the stencilsheet by applying asolution consisting of alum, glycerine and water toboth sides of the sheet, and subsequently drying the tempered sheet. v-I In testimony whereof, I have signed my name to this specification.

STERLING ELLIOTT.

